Documentation for distantpoint Values

We've always had a hard time seeing the planets in our sky, but since increasing the resolution of or system it's gotten much worse.

Looking into the documentation the values seem straightforward, but I notice some planets have slum/pointmax/polymax/polysize and some have distantpoint magnitude. Magnitude seems much easier, but I'm curious if it's straightforward maximum magnitude from earth/minimum from Earth or... what?

2.0

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There is a magnitude command, I cannot find any docs in the runtime syntax. Where did you find the documentation? I had to consult the source code and do some archeological digging.


Anywho, you can use the magnitude command to tweak the scaling, first is a maximum magnitude and the second is attenuation called "distance to earth" in AU. Defaults are -4.4 and 0.28 AU, yeah negative maximum magnitude... that is a silly name for a variable. Think of it as an magnitude exponent factor (see equation below).

Earth.distantpoint magnitude -1.0 0.28

These two values are used to calculate the pointsize rendered, but this is clamped to maxpointsize which is 4 by default. So make sure you scale up the pointsize.


Earth.distantpoint maxpointsize 16

The polysize might need scaling to match aswell (that's the glow around the point)

Earth.distantpoint maxpolysize 128


The pointsize calc goes something like so (is first value in magnitude command, d_min is second value in magnitude command):


pt_size = min(maxpointsize, 2.0 * sqrt(slum) * sqrt( 10^(-0.4*mag_max) ) * sqrt(1.0/ (d/d_min)^2 )

d : distance from camera to planet/distant point
mag_max : max magnitude (set by magnitude command)
d_min : distance from earth (set by magnitude command)


Oh, I was requesting documentation, since none exists. This is very helpful, thank you.


So the first magnitude value should really be the maximum visual magnitude of the planet (in which case, many of the planets are too low), or is that just the name of the variable? And then the second variable is minimum distance from Earth?

I guess I'm interested in how to get a behavior that predictably responds somewhat like the real planets. It seems like this will provide the core of that as long as everything is clear and straightforward. My only other note is making maxpointsize too big seems to leave the point up when flying to the planet, but there's not really a distancefade setting here?